Concatenation of 25 Histograms

I am currently doing face recognition system. I have calculated the normalized histogram for 25 subjects and now I want to concatenate the 25 histogram together in order to do classification using K-Nearest neighbor.

But the question is, how do I concatenate all these histogram together?

Answer 1

[Nick Counts]

Mansell,

Without seeing how you are storing these histograms, it is difficult to answer.

However, if you are using any of Matlab's built-in variable types (matrices, structures, even objects) you can use cat or any of its variants.

Look at:

help cat
help vertcat

I am not an expert on the kNN, but my guess is that your implementation is designed to operate on a matrix. In that case, you probably have a particular matrix shape (dimensions) that is required. Remember that Matlab matrices can have more than 2 dimensions.

    trainingSet1 = ones(10,2);
    trainingSet2 = ones(10,2)*2;
    trainingSet3 = ones(10,2)*3;

    allHistograms(1,:,:) = trainingSet1;
    allHistograms(2,:,:) = trainingSet2;
    allHistograms(3,:,:) = trainingSet3;

Hopefully something in here is helpful. Good luck!

Cheers